Safety attachment for presses



May 21, 1929. I ROCHE 1,714,049

SAFETY ATTACHMENT FOR PRESSES Filed Dec. 21, 1925 2 Sheets-Sheet 1 Fig.1.-

lnvenfor.

Michael J. Roche YH A1TY$F May 21, 1929. J, ROCHE 1,714,049

SAFETY ATTACHMENT FOR PRESSES Filed Dec. 21, 1925 2 Sheets-Sheet 2 Inventor. Michael J. Roche 'YMMW 40 1 clutch device is of the ordinary one-revolu I possibility of his. being able to invention applied thereto;

Patented I May 21, 1929.

STATES PATENT OFFICE..."-

1 MICHAEL J. ROCHE, or NEWTON CENTER; MASSACHUSETTS.

SAFETY ATTACHMENT r03 rarissns.

Application filed December 21, 1925. Serial no. 76,714 7 i This invention relates to a safety attachment. for presses, and particularly to a safety attachment of that type. in. which .the safety either hand in the danger zone when the press is operated.

In order to give an understandin of the invention I have illustrated in the rawings a selected embodiment thereof whichxwill now be described after which the novel features will be pointed out. in the appended claims.

Fig. 1 is a side viewof a press having my 1 Fig. 2 is a section on the line Fig.1; Fig.3 is a fragmentary perspective-view illustrating the clutch-tripping mechanism;

Fig. 4 is a section on the line 41-41, Fig. 1; Fig. 5 is a detail'of the clutch actuator.

In the drawings 1 indicates generally a punch press which maybe ofany usual construction and. which is provided with the bed 2 and theplunger 3' which carries the die. The plunger is guided in a guideway land is operated by means of the usual eccentric 5 on the drivin shaft ,6. The shaft is actuated from apu e 7 which is operatively con-" nected to the sha through a clutchdevice indicated generally at .8 and which may be of any usual or suitable construction. This tiontype and it is controlled by a controlling dog 9 which is pivoted to the pressa't 10. This type of clutch-is one which is very familiar and henceIzhave not thought it necessary to illustrateit herein. It is sufficient to say that when the controlling dog 9 isswung downwardly into the position shown in Fig. 5the clutch will be automatically engaged and when the dog is in its operative position shown infull lines Fi 3'it will'operate to disengage the clutch a ter the completion of one revolution. t

My invention relates to a novel two-hand mechanism (thatisa mechanism which requires the useof both hands to operateit) for tripping the clutch, said mechanism being so, constructed that'after the clutch is tripped it vwillmake but onerevolution and Will then'be automatically disengaged so that 1n order to trip it againit is necessary to again manipulate the two-hand mechanism. This will prevent the possibility of arepeat.

' I The .clutch is tripped by meansof a sliding actuator .11 .which" is mounted :for sliding movement in a bracket 12 carried bythe press frame and which requires for its operation the use of {both handsas will be presently described. 7 This slide 11 has alug 13 on its upper side which co-operates with a latch l l that ispivoted to the clutch dog 9..v Said doghas rigid therewith a depending arm 15 from which extends avpin or projection 16 against whichthe latch 14 rests.vv The projection 16 v limits the swinging movement of the latch in one direction, while permitting its free movement in the opposite di- 1 rection. When the parts are in the position shown in Fig. 3 thelatch 14 is situated between the projection 16 and thelugi 13.. With the parts in this position a movement'of the slide 11 to theleft will operate'through the 1 lug 13 and latch 1a to swing the, clutch 'dog9 downwardly as shown in dotted lines Fig.1 3

and in full lines Fig. 5, which will-permit-the clutch to'be thrown intoeng'agement.

The mechanism for operatingthe clutch actuator. ll'is such as tocause. the slide to move into the. dotted line position Fig. 5 in which position the projection .l3has wiped past the end of the latch 14 thus releasing the clutch dog and allowing it to assume its normal position'shown. in full'lines Fig.8. under the influence of a spring 17., v

.The clutch dog 9 will thus cause adisengagement-of the clutch after it has made one revolution'a'nd the clutch can only be tripped againby returning the slide .11 ,to, the full line position Fig. 3 and then moving it again toward the left. During the returnmovement of the slide to the full lineposition Fig. '3 the projection 13 will wipe under'the latch 14, the latterswinging away from the stud 16 to permit, this operation.

As stated bove the actuatingislide lli'lS operated by a two-hand mechanism whichrequires the use of both of the operatorshands to 'manipulate'it- Said slide 11 is connected by meansof a link,

18 to an arm 19 fast on a 'vertical l shaft 20 which is journalled in suitable bearings 21 carried by the press. Rocking movement of the shaft 20, therefore, will operate to give the slide 11 its sliding movement.

To erate the shaft I have provided the fol owing mechanism. Pivoted. to the press at each side thereof is a lever, said levers being indicated at 22 and 23respectively. These levers are pivoted at 24 to brackets 25 on the side of the press. These levers extend forwardly tothe front of the press and are provided. with handles 26 by which they maybe operated. The two levers are connected'to the shaft'20,thelever 23 being connected to an arm 27 fast on the shaft 20 and the lever 22 being connected to a link 28 which in turn is connected to another arm 29 fast on the shaft 20. The connection between thelever 23 and the arm 27 is a pin-and-slot connection to prevent binding of the parts.

Each lever has associated therewith a locking device which normally looks it in the position shown in full lines Fig. 4 and the locking devices are constructed so that they can only be released by the hands of the operator when he grasps the handle 26.

Each lever 22 has a locking latch 30 pivoted thereto at 31, these latches co-operating with teeth 32 on brackets 33 which are se cured to the press at each side thereof. Each locking latch has a handle 34 rigid therewith and by which it may be manipulated to release it from the bracket 33. The position of the levers 22 23 shown in Fig. 4 corresponds to the position of the actuatingslide 11 in Fig. 3 and in order to move the slide to the left Fig. 3 to disengage the clutch it isnecessary to swing the levers 22 into the dotted line position Fig. 4. This can only be accomplished by releasing both locking latches 30. i

The handles 34 are so positioned that when the'operatorgrasps the handles 26 he also grasps the handles 34 and'by pressing the handles 34 toward the handles 26 the springpressed locking latches 30 will be disengaged from the teeth 32. operator to swing the levers 22 into the dotted line position Fig.4 and thus turn the shaft 20 and move the clutch actuator 11 into the dotted line position shown in Fig. 5. During this movement the clutch is tripped as above described and as soon as the projection 13 has passed the nose of the latch 14 the clutch dog will return to its operative position.

In order to trip the clutch a second time it 7 is necessary for the operator to return the levers 22, 23 to the full line position Fig. 4, which will return the slide 11 to its fullline position Fig. 3 and then to swing the lovers outwardly into the dotted 'line position again and this can only'be' done in case the operator has both handsengaged in manipulating the two levers. With this device it'is impossible for the This will permit the operator to have either ofhis hands in the danger zone at the time when the clutch is ratchet member 36 provided with teeth 37.

These teeth co-operate with looking members 38 which are slidably mounted in boXes139 secured to-the press frame. Each of these locking members 38 is acted on by a: spring 40 which tends to force it inwardly, each spring acting at one end against a collar 41 fast on the corresponding member 38 and at the other end actingagainst the end of the housing 39. The outer end ofeach locking member3S is provided with a head 421ming-a slot 43 thereinin which is received a pin 44 carried by the corresponding lever.

When the parts are in-the position shown in full lines Fig. 4 the levers 22; 23 are locked by the-locking pawls 30 and the locking members 38 also lockthe plunger from downward movement by their engagement with theteeth 37. lVhen the levers 22, 23 are swung outwardly to tripthe clutchsaid swinging movement will operate to withdraw the locking members 38 from looking engagement with the plunger thus unlocking the plunger.

It is the intention that the locking members 38 should lock the plunger in its raised position, which is the position the plunger occupies when the clutch is disengaged.

In'order to prevent the pawl from being accidentally thrown into locking engagement with the teeth'37 after the clutchhas been tripped and when the plunger is moving downwardly, an occurrencewhich would be likely to cause damageto the parts, I have provided guards 420 in the fornrof plates which overlie the upper teeth 37 ofthe rack. These guards will be so adjustedthat they willcover allof the ratchet teethabove the one which is in engagement with the locking member 38 when the plunger is fullyraised. If, therefore. after the clutch is tripped and the plunger startsjits downward movement the locking members are accidentally moved inwardly they will engagethe guard members 420 and will be prevented thereby from looking into the ratchet teeth. Hence this device will provide means for locking the plunger in its elevated position but will prevent the lock from becoming operative after the plunger starts downwardly.

The rack members 361are preferablysecured-to the plunger so that they can be ad- 'usted as necessary to cause the locking memers 38 tofunction properly.

With my invention, therefore, it will not.

be possible for a person to place his hand in the danger zone while the press is operated because in order to operate the press the operator is required to use both hands to manipulate the levers 22, 23.

Furthermore, the construction'has the advantage that a repeat is not possible since the operative connection between the actuator 11 and the clutch dog is disrupted after the clutch is disengaged and can only be reestablished by again returning the actuator 11 to the full line position shown in Fig. 3.

I claim: 1. In a safety device for presses operated by a one-revolution clutch, the combination with a clutch actuator having a two-and-fro movement, movement in one direction operating to trip the clutch, and means for operat ing the actuator comprising two levers and a lock for each lever which is released by grasping the lever, both of which looks must be released at the same time in order to permit the operation of the levers.

2. The combination with a press having a vertically-moving plunger, of a clutch for operatin connected to the plunger, a locking pawl cooperating with each plunger to lock the plunger against downward movement two levers pivoted to the press, each lever being connected to one of the locking pawls, whereby both levers must be actuated to unlock the said plunger, two ratchet members,

plunger, and a clutch-tripping member which is connected to and operated by both levers. V

3. In a device of the class described, the combination with a spring-actuated clutchcontrolling member adapted to control a onerevolution clutch pivoted to said controlling thereby allowing the controllin member to return tooperative position, sai latch being swung away from the stop by the projection on'the return movement of the actuator, and means to operate the actuator.

4. The combination with a'press, of two levers pivoted thereto each having a handle,

means connecting said levers whereby they operate in unison, a lock normally locking each lever from movement, each lock being adapted to be released by grasping the handle of the corresponding lever, and means actuated by said levers for controlling the operation of the clutch.

In testimony'whereof, I have signed my name to this specification.

MICHAEL J. ROCHE. 

